Normalize Excel file types when resolving parser rules and applying the
xlsx_first_row_as_header override for both xlsx and xls. Skip the override
for non-builtin engines, unify legacy XLS parsing with the XLSX default path,
and extend tests for case handling and explicit false overrides.
WPS embeds images in cells using =DISPIMG("ID",mode) which may appear as plain text prefixed with "_xlfn." when processed by openpyxl. These function strings pollute the RAG-indexed document content, causing incorrect AI recall.
Add a regex filter (_is_image_function) that detects _xlfn.DISPIMG(...) and _xlfn.IMAGE(...) patterns and excludes them during row processing in ExcelParser.parse_into_text().
Refs: https://github.com/Tencent/WeKnora/issues/1779
Introduce opendataloader and PaddleOCR-VL parser engines with tenant-level
settings UI, replace liteparse, and harden Excel/PPT/Markdown parsing.
Optional odl-hybrid sidecar stays local-build only and is excluded from
default dev-start and full profiles.
wizardchen